A sea turtle rescued by northern beaches lifesavers will be under expert care for at least a month.

The female hawksbill was found floating on the South Curl Curl shoreline on Saturday, October 6.

The animal, dubbed Curly, was rescued by volunteer life savers and is now being cared for by Manly Sea Life Sanctuary.

Life sciences manager Rob Townsend said the turtle might have eaten discarded plastic but it was still not clear what was wrong with the animal. A number of tests will be done. The turtle had no visible physical injuries.

"It's very early days. We don't know what her issues are," Mr Townsend said.

But Mr Townsend was optimistic about being able to set the animal free in due course.

"It's really hard to tell (how long the turtle will have to stay at the sanctuary) for several months yet.